The 13th Floor — Kay Bergstrom

One woman disappeared there. Another is trapped there. Fear lives there...

Newly hired to at her job, Petra Gaines learns that the woman she has replaced, Becky Stanley, was not fired but instead disappeared without a trace from her thirteenth-floor office.

Research specialist Petra Gaines senses that things are not quite right at her new job. Her predecessor disappeared without any notice or explanation. When Petra sees the terrified face of a woman in the bathroom mirror, she thinks she's found the missing employee--especially when she finds the note on her desk reading: Don't tell them anything. They want to hurt me. . . .